An Efficient, Sunny Family Retreat

RMI’s Victor Olgyay turned his family’s 1950s ranch into a comfortable, efficient home infused with solar-smart design.

Solar thermal collectors on the lower roof and a solar PV array on the higher roof supply the home’s hot water and electricity. Image copyright Rocky Mountain Institute by Peter Bronski.

Humans are adaptable creatures. We’ll stubbornly walk with a stone in our shoe, but are happier when we remove it. That certainly should be true with our homes. Rather than change ourselves to fit the home we get, we can adapt our homes to fit us better. Like a shoe, they can stretch to provide comfort, rather than force our feet to fit.

In 2004 my wife, Kristy, and I had our second daughter and bought a small 1950s ranch conveniently located in central Boulder, Colorado. We could walk to work, and our lot has a beautiful, mature hackberry tree on which we hung a swing. The house was cozy and as we lived in it, we gradually made it more so. We insulated and weatherstripped it. We planted a vegetable garden. We spent a couple hundred dollars on natural gas per year, and got itty-bitty annual electricity rebate checks from Xcel, our utility, thanks to a 4-kW solar PV system we put on the roof. The house felt like a good fit.

But as our children grew, we found our family needed more space. So in 2011, we took the plunge and renovated the house. We added a 900-square-foot second floor, nearly doubling the square footage from 1,200 to 2,100.

Since we were tearing up the place, it was an ideal time to do a few other performance upgrades. We switched out the existing double-pane, low-e windows (with terrible frames) for quad-pane, fiberglass-frame windows with an overall unit average of R9. We decreased our home’s north-facing glass and increased it on the sunny south side. We calculated the overhangs to provide passive solar heating in the winter and shading in the summer. All the new windows are casements or awnings so they lock airtight when we want them to, and catch the wind when open for increased ventilation.

Right-sized overhangs
on the south side of
the house keep the
summer sun out of
windows with passive
solar design. Image copyright Rocky Mountain Institute by Romy Purshouse.

And we did a million other things. We reused as much of the old roof framing as possible, framing the upstairs walls with the 2x8 rafters, stuffing them with cellulose, and wrapping the whole house with two inches of rigid insulation to eliminate thermal bridges. The roof is framed with R40 SIPs. We used an ENERGY Star-rated light-colored roofing material, and local beetle-kill pine for all the soffits and trim.

So the house performs well, using about one-tenth the energy of a typical efficient house. But most importantly, once again it’s a comfortable fit. It’s 95 degrees Fahrenheit outside in Boulder as I write these words in midsummer, and inside the house it is 76 … and we have no AC. We open the windows at night and close them during the day.

Yet the true comfort is in how we use the house, and how it supports our lives. Our kids love the balcony over the living room; they can spy on the adults or fly airplanes down on unsuspecting targets. The community spaces — living room, play room, deck — gather us as a family, while private spaces let us take quiet time. The 1-watt LED lights built into the stair risers cast an amber glow on the adjacent wall, safely and satisfyingly identifying the steps. Their warm, low-color temperature and low light levels have the least amount of impact on sleep cycles and the body’s melatonin production, allowing people to traverse at night without triggering their brains to wake up any more than necessary. And the west side of the house, nestled under the shade of the big hackberry tree, is lousy for solar collection, but a great place to plant a green roof. With a view of the Rocky Mountains’ foothills, our kids think it’s the best room in the house. Architecture must support life first.

The rest of the roof, it collects rain and sun. We pulled off the existing 4-kW PV system during the renovation and reinstalled it after. We are still effectively net zero for electricity — the average American home consumes ~10,800 kWh of electricity per year; between July last summer and June this summer, we consumed just 96 from our utility. And because our house is significantly more airtight than it used to be, we decided to get rid of all combustion within the building envelope. No fireplace, no gas water heater, no carbon monoxide. We have an inexpensive electric water heater as back up, but most of our domestic hot water comes from the sun. We added a solar thermal system with three collectors yielding 90 kBtu/day average — enough for all our needs in the winter and more than enough in the summer, so we store the extra heat in our hot tub. Indulgent, but it makes our night.

We still have much to do to make the house more efficient, including replacing our 15-year-old refrigerator and dishwasher. But in the meantime, we have fruit trees and a garden, and a home that’s comfortable, efficient, and connected to nature. Our little 6,000-square-foot landscape is diversifying, encouraging more pollinators to visit, birds to spread seeds, and other ecosystem services to flourish. As a family we are adapting to environmental concerns, and slowly working to improve our individual and collective lives. Our home needs to fit us, and by doing so, it also better fits the planet.

Written by Victor Olgyay, AIA, a bioclimatic architect and a principal in RMI’s buildings practice. Follow Victor on Twitter.

This article is from the Summer 2014 issue of Rocky Mountain Institute’s Solution Journal. To read more from back issues of Solutions Journal, please visit the RMI website.

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